A quadruple tandem image forming apparatus in the past operates according to a procedure explained below. The image forming apparatus forms toner images respectively on the surfaces of photoconductive members for Y, M, C, and BK and transfers the toner images on the photoconductive members onto an intermediate transfer member. The intermediate transfer member transfers the toner images onto a medium. The medium having the toner images transferred thereon passes through a fixing apparatus. The fixing apparatus heats both the surfaces of the medium while pressurizing the surfaces to fix the toner images on the medium. The medium passed through the fixing apparatus is discharged to a paper discharge tray.
Incidentally, the fixing apparatus is deprived of heat by coming into contact with the medium. Therefore, temperature control is performed to keep the temperature of the fixing apparatus at a predetermined temperature. If abnormality occurs in which fixing temperature during printing deviates from a normal temperature range, a printing operation is suspended and temperature control for returning the fixing temperature to normal fixing temperature is performed. The printing operation is resumed when the fixing temperature returns to the normal temperature range.